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The optimization of vanadium redox flow batteries (VRFBs) is closely related to the flow rate control: a proper regulation of the electrolyte flow rate reduces losses and prolongs battery lifetime. To this end, a flow factor control strategy in VRFBs was proposed in the literature provided with numerical/experimental validations. Yet, a theoretical justification of this approach was lacking. The respective control law is a generalization of Faraday’s law of electrolysis since it employs a special scaling parameter referred to as the flow factor. In this paper, we show that this coefficient is directly related to the conversion rate of electrolyte in the cell. Furthermore, we pose an optimal control problem with maximization of total battery power integrated over time to determine an optimal flow factor. To this end, we use a simple stochastic policy gradient algorithm. The case studies illustrate the application of the computed optimal controller under various load currents and demonstrate that there is no single flow factor for all modes, the optimal performance of the battery can only be guaranteed by different values of this parameter. As a result, the proposed control strategy can be used for advanced control and monitoring tools for industrial VRFB systems.

The article presents a brief biography of the little-studied British deist Thomas Chubb (1679-1747) and a reconstruction of his ideas about capabilities of human mind. The goal of this article is to study the religious philosophy of T. Chubb that Russian studies does not distinguish from ideas of other deists. That is why the idea of the phenomenon of deism is still less clear in relation to foreign studies. The article analyzes and presents Chubbs concepts about the independence of religious truths from human perception, that are presented in «Discourse concerning Reason, with Regard to Religion and Divine Revelation» (1733) and «An Enquiry into the Ground and Foundation of Religion». The article documents that the English philosopher formulated three "author's" truths of natural religion: there is an initial difference between objects, independent of human perception; this distinction is the basis for human behavior; God made these foundations a moral rule for all people and for himself. The work identifies and analyzes the definition of the phenomenon of "deism" in Chubb's treatises, as well as an assessment of his philosophy in the context of this definition – the natural religion of reason or belief and just and sense of a Deity impressed upon the mind, and is the governing principle of a man’s-affections and actions. The correlation of the ideas of Thomas Chubb and Matthew Tindal is analyzed. At the end of the article, a brief conclusion is made about the place of T. Chubbs philosophy to deism in general. The author of this work believes that despite the absence of references to other deists by the English philosopher, the ideas of this thinker fit into their religious and philosophical system, specifically about the issue of understanding natural religion. The sources of this article are treaties «The Sufficiency of Reason in Matters of Religion, Farther Considered» (1732), «Discourse concerning Reason, with Regard to Religion and Divine Revelation» (1733), «Some reflections upon the comparative excellency and usefulness of moral and positive duties» (1733), «The true Gospel of Jesus Christ Asserted»(1741) and several other treatises.

Current limitations of spintronics devices based on bulk topological materials stimulate the search for new materials and structures with interesting spin properties. Here the authors report a chiral spin texture around the Fermi level related to structural symmetry breaking in a TaSe2 layer grown on a Bi2Se3 surface.

The controllability function method, introduced by V. I. Korobov in late 1970s, is known to be an efficient tool for control systems design. It is developed for both linear/nonlinear and finite/infinite dimensional systems. This paper bridges the method with the homogeneity theory popular today. The standard homogeneity known since 18th century is a symmetry of function with respect to uniform scaling of its argument. Some generalizations of the standard homogeneity were introduced in 20th century. This paper shows that the so-called homogeneous norm is a controllability function of the linear autonomous control system and the corresponding closed-loop system is homogeneous in the generalized sense. This immediately yields many useful properties known for homogeneous systems such as robustness (Input-to-State Stability) with respect to a rather large class of perturbations, in particular, with respect to bounded additive measurement noises and bounded additive exogenous disturbances. The main theorem presented in this paper slightly refines the design of the controllability function for a multiply-input linear autonomous control systems. The design procedure consists in solving subsequently a linear algebraic equation and a system of linear matrix inequalities. The homogeneity itself and the use of the canonical homogeneous norm essentially simplify the design of a controllability function and the analysis of the closed-loop system. Theoretical results are supported with examples. The further study of homogeneity-based design of controllability functions seems to be a promising direction for future research.

One of the promising methods for rock cutting technology is the use of high-speed water jets. In order to improve the cutting capacity of water jets without increasing the hydraulic power of equipment, pulsed water jets are basically used to increase the rock cutting efficiency. However, there are no mature recommendations for selection of rational parameters, and the relationship between indicators of rock cutting efficiency and parameters of pulsed water jet is still not established. In this context, we aimed at developing a generalized equation for calculating rock cutting efficiency, in which all the major parameters in consideration of rock cutting process are included. Then, a calibration of the rational parameters of rock cutting by pulsed water jets was conducted. The results are likely helpful for increasing productivity and reducing energy consumption. Keywords: Pulsed water jets, Rock cutting, Water jet technology, Generalized equation, Depth of cut

Active volcanoes are associated with microearthquake (MEQ) hypocenters that form plane-oriented cluster distributions. These are faults delineating a magma injection system of dykes and sills. The Frac-Digger program was used to track fracking faults in the Kamchatka active volcanic belt and fore-arc region of Russia. In the case of magma laterally injected from volcanoes into adjacent structures, high-temperature hydrothermal systems arise, for example at Mutnovsky and Koryaksky volcanoes. Thermal features adjacent to these active volcanoes respond to magma injection events by degassing CO2 and by transient temperature changes. Geysers created by CO2-gaslift activity in silicic volcanism areas also flag magma and CO2 recharge and redistributions, for example at the Uzon-Geyserny, Kamchatka, Russia and Yellowstone, USA magma hydrothermal systems. Seismogenic faults in the Kamchatka fore-arc region are indicators of geofluid fracking; those faults can be traced down to 250 km depth, which is within the subduction slab below primary magma sources.

Most HIV-1 tropism studies have involved non-A subtypes. Our aim was to study the prevalence of R5- and non-R5-tropic HIV-1 variants and the tropism occurrence relative to the CD4 counts, treatment experiences, transmission routes and other features of infection in Russia, where subtype A is presumably predominant. In this multicenter, single-step, cross-sectional, epidemiologic study, 943 HIV-1-infected patients were enrolled at 12 AIDS centers throughout Russia. Viral tropism was determined using a genotype method-based kit. The V3 loop sequences were analyzed using the geno2pheno resource. The tropism was successfully predicted for 823 (87.3%) patients. Frequencies of R5-tropic and non-R5-tropic viruses in successfully analyzed samples were 70.2% (578) and 29.8% (245), respectively. Co-receptor usage correlated significantly only with the treatment experiences (p = 0.018) and CD4 counts (p = 0.004). But there was no dependence of R5/non-R5 co-receptor usage frequencies on presence/absence of a therapy change (p = 0.664) or HIV infection duration (p = 0.458). According to the env sequences, 457 (83.6%) of the samples in study were subtype A and 70 (12.8%) were subtype B. This indicates a stabilizing of immune system and thus little emergence of X4 viruses. We suggest that CCR5-antagonists could be used in both naïve and experienced patients in Russia after determination of HIV tropism.

Genetic diversity between of the Novosibirsk and Tomsk chromosome races of the common shrew (Sorex araneus) was analyzed using 39 polymorphic AFLP (amplified fragments length polymorphism) markers. Exact and F-statistics tests for population differentiation demonstrated significant interracial difference in allele frequencies and significant subdivision between the races. The value of the genetic distance between the chromosome races observed in this study corresponds to that found between subspecies of mammals studied so far.